Polymeric epoxides



' chloride,

United States Patent 3,135,706 POLYMERIC EPGXlDES Edwin J. Vandenherg,Wilmington, DeL, assignor to Hercules Powder Company, Wilmington, Dei, acorporation of Delaware No Drawing. Filed May 11, 1959, Ser. No. 812,08014 Claims. (Cl. 2602) This invention relates to a new process ofpolymeriz ing epoxides and more particularly to an improved process ofpolymerizing epoxides with an organoaluminum compound. 7

In accordance with'this invention, it has been discovered that greatlyimproved results are obtained in the polymerization of epoxides when anorganoaluminum compounds that has been reacted and/or complexed with achelating agent within a given molar ratio is used as the catalyst forthe polymerization. By using these chelated organoaluminum compounds ascatalysts it has been found that much higher molecular weightpolyepoxides are generally obtained than when the aluminum compound isnot chelated. In many cases, the conversion and/ or yield of highmolecular weight polymer is greatly increased. Another advantage in theuse of these chelated aluminum compounds is in the greatly increasedrate of polymerization that may be realized in many cases. Any epoxidewherein the epoxy group is an oxirane ring may be homopolymerized orcopolymerized with a second epoxide by the process of this invention toobtain improved results. Exemplary of the epoxide that may behomopolymerized or copolymerized are the alkylene oxides such asethylene oxide, propylene oxide, butene oxides, isobutylene epoxide,substituted alkylene oxides such as epichlorohydrin, epibromohydrin,methallyl chloride epoxide, trifluoromethyl ethylene oxide,perfluoropropylene oxide, perfluoroethylene oxide, vinyl chlorideepoxide, dichloroisobutylene epoxide, etc., cycloaliphatic epoxides suchas cyclohexene oxides, vinyl cyclohexene monoxide, vinyl cyclohexenedioxide, dipentene epoxide, etc., epoxy others such as alkyl glycidylethers as, for example, methyl glycidyl ether, ethyl glycidyl ether,isopropyl glycidyl ether, isobutyl glycidyl ether, tert-butyl glycidylether, n-hexyl glycidyl ether, n-octyl glycidyl ether, etc., phenylglycidyl ether, chlorophenyl glycidyl ethers, nitrophenyl glycidylethers, alkylphenyl glycidyl ethers, chloroalkyl glycidyl ethers, suchas chloroethyl glycidyl ether, unsaturated glycidyl ethers such asvinylglycidyl ether, allyl glycidyl ether, etc., glycidyl esters such asglycidyl acetate, glycidyl propionate, glycidyl pivalate, glycidylmethacrylate, glycidyl acrylate, etc., alkyl glycidates such as methylglycidate, ethyl glycidate, etc., md other epoxides as, for example,styrene oxide, a-methylstyrene oxide, butadiene monoxide, butadienedioxide, epoxy stearates, l-dimethylamino-2,3- epoxy-propane, trimethyl2,3-epoxypropyl ammonium etc. Particularly outstanding results areachieved in the polymerization of ethylene oxide and its monosubstitutedderivatives such as propylene oxide, epihalohydrins, etc. As pointed outabove, any of these epoxides may be homopolymerized or any mixture oftwo or more may be copolymerized.

Any trihydrocarbonaluminum or dihydrocarbonaluminum hydride or complexthereof may be reacted with the chelating agent to produce the catalystsused in accorda-pinene epoxide,

.",l35,706 Patented June 2, 1964 Ice ance with this invention, thehydrocarbon radical being an alkyl, cycloalkyl or aryl radical.Exemplary of these aluminum compounds are trimethylaluminum,triet'nylalurninum, tripropylaluminum, triisopropylaluminum,triisobutylaluminum, trihexylalurninum, trioctylaluminum,tricyclohexylaluminum, triphenylaluminum, etc., and the correspondingdihydrocarbonaluminum hydrides such as diethylaluminum hydride,diisobutylaluminum hydride, etc., and their complexes such as the alkalimetal aluminum tetraalkyls and alkyl hydrides, as for example, lithiumaluminum tetraalkyls, sodium aluminum tetraalkyls, sodium aluminumtrialkyl hydride, etc. As pointed out above, these trialkylaluminums anddialkylaluminum hydrides are reacted with a chelating agent, i.e., acompound containing a chelate group, prior to their use as catalysts forthe polymerization of epoxides in accordance with this invention.Iustwhy the chelatedaluminum alkyls are so effective in producing muchhigher molecular weight polyepoxides and/ or increased yields of polymeris not known. However, it has been found that this result is obtainedwhen a diallcylaluminum hydride or trialkylaluminum is reacted with fromabout 0.1 to about 2 moles of chelating agent per mole of aluminum,preferably with from about 0.2 to about 15 moles and more preferablywith about 0.3 to about 1.0 mole per mole of aluminum alkyl. The optimumratio will, of course, depend on the type of chelating agent, thealuminum alkyl, etc. If more than one chelating group is present in thechelating agent, the amount used will be proportionately lower.

Any organic compound that is capable of forming a ring by co-ordinationwith its unshared electrons and the aluminum atom maybe used. Preferablythese chelating agents are characterized by two functional groups, oneof which is an 'OH group or SH group, as, for example, a hydroxyl, or anenol of a ketone, sulfoxide or sulfone, an OH of a carboxyl group, etc.,which -OH or --SH group interacts with the trialkylaluminum ordialkylaluminum hydride to form a conventional, covalent aluminum-oxygenor aluminum-sulfur bond according to the following equations:

where R is alkyl and R is hydrogen or alkyl. The sec- 11 I n carbonyl(O), ester (COR), carboxyl (COH) sulfoxide ,su1rone S S ll ll amino(R:N), thiocarbonyl (-0-), thiocarboxylic (C-SH) S ll thio esters (-0-0B), etc., groups Such chelating agents can thus form from the trialkylaluminum or dialkylaluminum hydride a cyclic compound of the followingstructure:

Al-(l) R Xn where R is alkyl, Y is carbon, sulfur, or nitrogen and Xrepresents the carbon, nitrogen, and oxygen atoms that maybe presentbetween the YZ group and the OI-I Where geometric isomers exist, as forexample, a and [3 forms of some ketoximes and syn, anti, and amphi'formsgroup in the chelating agent, 11 being the number of such atoms.Chelating agents with an SH group form a cyclic compound of the sametype but with S in place of'O. In the case of chelating agentscontaining the group -N= C-SH, the chelate may be a 4 atom cycliccompound. For example, with inercaptobenzothiazole, the chelate is a 4atom cyclic compound which may have the formula:

The ring size formed with the aluminum by the chelating agent preferablycontains five or six atoms including the aluminum, but rings with fourand seven atoms'are also operable. Thus, n, in the above formula ispreferably 2 but may be 0 to 3. The optimum ring size and the preferredchelating agent may vary somewhat with the nature of the substituentgroups in the chelating agent as well 2,4-pentane-dione, etc.,ketoacids, such as acetoacetic 'acid, ketoesters such as ethylacetoacetate, ketoaldehydes such as formylacetone, hydroxyketones suchas hydroxyethyl methyl ketone, hydroxyacetone, o-hydroxyacetojphenone,2,5 dihydroxy-p-benzoquinone, etc., hydroxyaldehydes such assalicylaldehyde, hydroxy esters such as ethyl glycolate, 2-hydroxyethylacetate, dicarboxylic acids and their esters such as oxalic acid,malonic acid, etc.,

monoesters of'oxalic acid, monoand diesters of malonic acid, etc.,dialdehydes such as malonaldehyde, alkoxyacids such as ethoxyaceticacid, ketoximes such as 2,3-butane-dione-monoxime, dialdehyde monooximessuch as glyoxal monoxime, hydroxamic acids such as N-phenylbenzohydroxamic acid, dioximes such as dimethyl glyoxime,:nitrocompounds such as 1,3-nitroalcohols, 1,3-

nitroketones, 2-nitroacetic acid, nitroso compounds such as1,2-nitroso-oximes, amino alcohols such as ethanolamine,diethylaminoethanol, 8-hydroxyquinoline, ,3-diethylaminopropylene oxide,1,3-imino alcohols such as 3-imino-butanol-1, bis salicylaldehydeethylene diimine (Schiifs bases), l-3-keto (or aldo-)-imides such asacetylacetone mono-imide, mercaptothiazoles, etc. Chelating agents withtwo or more chelating functions may also be used, as for example,2,S-dihydroxy-p-benzoquinone, tetrahydroxyethylethylene diamine, bis(l,3 diketones) such as (CH CO) CHCH(COCH (CH CO) CH(CH CH (COCH 2 wheren is 2,6, or 10, bis(l,2-ketoximes), bis(1,2 dioximes), etc. V

The chelate structures which can exist in two or more similar resonatingforms are especially effective, as for example when X has a double bondsuch as a C=C or C==N group in conjugation with a YZ carbonyl whichoccurs in the case of 1,3-diketones, 1,2-ketoxirnes, etc.

of some dioximes, it is generally preferable to use the 0:, anti andamphi forms or conditions where the compound will isomerize to thedesired form, since these forms generally yield better chelates.

Any desired procedure may be used for reacting the alkylaluminumcompound with the specified molar ratio of chelating agent. It isreadily done by adding the specified amount of chelating agent graduallytoa solutionof the alkylaluminum compound in an inert diluent as, for

example, a hydrocarbon diluent such as n-hexane, toluone, or an ethersuch as diethyl ether, tetrahydrofuran,

etc., or a mixture of such diluents. It may also be done in the absenceof a diluent. .The alkylaluminum chelate may be used immediately afterpreparation or it may be aged or, if desired,'heat-treated in somecases. It is also possible to form the chelate in situ. If desired, thealkyl-' aluminum chelate may be used in combination with otherorganoaluminum compounds.

Any amount of the alkylaluminum chelate maybe used to catalyze thepolymerization process in accordance with this invention from a minorcatalytic amount up to a large excess but, in'general, will be withinthe range of from about 0.2 to 10 mole percent based on the monomerbeing polymerized and preferably will be within the range of from about1 to about 5 mole percent. based on the monomer being polymerized. Theamount used depends in part on such factors as monomer purity, diluentpurity, etc., less pure epoxides and diluents requiring more catalyst todestroy reactive impurities. In order to decrease catalyst consumption,it is generally preferred that impurities such as carbon dioxide,oxygen, aldehydes, alcohols, etc., be kept at as low a level aspractical. I

The polymerization reaction may be carried out by any desired means,either as a batch or continuous process with the catalyst added all atone time or in increments during the polymerization or continuouslythroughout the polymerization. .If desired, the monomer may be addedgraduallyto the polymerization system. It may be carried out as a bulkpolymerization process, in

some cases at the boiling point of the monomer (reduced to a convenientlevel by adjusting the pressure) so as to remove the heat of reaction.However, for ease of operation, it is more generally carried out in the'presence of an inert diluent. Any diluent that is'inert under thepolymerization reaction conditions may be used as, for example, etherssuch as the dialkyl, aryl or cycloalkyl ethers as, for example, diethylether, dipropyl ether, diisopropyl ether, aromatic hydrocarbons such asbenzene, toluene, etc., or saturated aliphatic hydrocarbons andcycloaliphatic hydrocarbons suchas n-heptane, cyclohexane, etc., andhalogenated hydrocarbons as, for example, chlorobenzene or haloalkanessuch as methyl chloride, methylene chloride, chloroform, carbontetrachloride, ethylene dichloride, etc. Obviously, any mixture of suchdiluents may be used and in many cases is preferable. t

The polymerization process in accordance with this invention maybe'carried out over a wide range of temperature and pressure. Usually,it will be carried out at a temperature from about '80 C. to about 250 Cpreferably from about C. up to about 150 C. and more preferably withinthe range of about 30 'C. to about C. Usually, the polymerizationprocess will be carried out at autogeneous pressure, but superatmos-.pheric, pressures up'to several hundreds pounds may be used of desiredand in the same way, subatmospheric pressures may also be used. a

The following examples exemplify the improved results that may beobtained on polymerizing epoxides in accordance with this invention. Allparts and percentages are by weight unless otherwise indicated. Themolecular weight of the polymers produced in these -was used in Examples1218 and 20-21.

examples is shown by the reduced specific viscosity (RSV) given foreach. By the term reduced specific viscosity is meant the /C determinedon a solution of the polymer in a given diluent. Thus, in the case ofthe poly(epichlorohydrins) the RSV is determined on a 0.1% solution ofthe polymer in a-chloronaphthalene dissolved at 100 C. and the viscositydetermined at that temperature. The diluent, concentration andtemperature at which the RSV is determined are stipulated for eachpolymer.

EXAMPLES 1 AND 2 Polymerization of Epz'chlorohydrin Each of threepolymerization vessels free of air were charged under nitrogen withdiethyl ether and parts of epichlorohydrin. After equilibrating at 30C., a solution of the catalyst was injected. The catalyst solutions wereprepared by diluting three parts of a solution of triethylaluminum inn-heptane with two parts of ether, one portion of this solution beingused as the control, and adding acetylacetone in an amount equal to onemole permole of triethylaluminum in another portion and in an amountequal to two moles per mole of triethylaluminum in another portion andagitating these solutions at 30 C. for 20 hours. The amount of catalystsolution injected into each polymerization vessel was that equivalent to0.74 part of the triethylaluminum reacted with the acetylacetone. Thetotal amount of diluent present in the system was 17.6 parts of which12% was n-heptane and 88% was ether. After agitating the polymerizationreaction mixtures at 30 C. for 19 hours, the polymerization was stoppedby adding 4' parts of anhydrous ethanol. luted with about 40 parts ofdiethyl ether, after which the ether-insoluble polymer was collected andwashed with ether. It was further purified by slurrying the polymer witha 1% solution of hydrogen chloride in ethanol,

The mixture was then diagain collected, washed with methanol, then withan 7 0.4% solution of 4,4'-thiobis(6-tert-butyl-m-cresol) in methanoland finally was dried for 16 hours at 50 C. under vacuum. The RSV ofeach of these polymers was determined on a 01% solution ina-chloronaphthalene at 100 C. Tabulated below is the RSV and the amountof polymer expressed as percent of the total polymer along with thecontrol where no chelat ng agent was used, Ex-

ample 1 where the triethylaluminum was chelated with a 1:1 mole ratio ofacetylacetone (A) and Example 2 with a 2:1 ratio of acetylacetone.

EXAMPLES 3-23 Polymerization of Ethylene Oxide In these examples, 10parts of ethylene oxide was polymerized following the general proceduredescribed above in Examples 1 and 2 except that the diluent was agentsin a ratio of 0.5 mole in Example 22 and 0.25 mole in Example 23 ofchelating agent per mole of aluminum. The ether-insoluble poly(ethyleneoxide) produced in each case was isolated as was thepoly(epichlorohydrin) in Examples 1 and 2 except that the hydrogenchloride used in the purification step was dissolved in an 80:20 mixtureof etherzmethanol instead of ethanol. The RSV of each of thepoly(ethyleneoxide)s was determined on a 0.1% solution of the polymer inchloroform at 25 C. In Table I are set forth the reaction time andtemperature used in each case, the chelated catalyst expressed astriisobutylaluminum (or triethylaluminum) +mole of chelating agent permole of aluminum, the RSV of the polymer and amount of the polymerexpressed as percent of the total polymer.

TABLE I Ether-insol- Reaction uble polymer isolated Ex- Catalyst amplePercent Time, Temp, RSV oftotal hrs. C. polymer C(gn-1 (i-O4H )3Al 19 400.78 50 re 3 (i-C4H )3Al+0.5 (2-hydroxy- 19 40 2.7 50

ethyl acetate). 4 (i-O4H )3Al+0.5(2'eth0xy 19 40 2.8 19

acetic acid). 5 (i-C4H )aA1+O.5 hydroxy- 19 40 3.5 57

acetone. 6 (i-fihghhAl-l-Oe salieylalde- 19 30 2.1 33

y e. 7 (1-C H )aA1+0.5 hydroxy- 19 30 2.0 100 acetophenone. 8(i1(134g[9);Al+1.0salicylalde- 43 30 3.9 50

y e. 9 (i-O4H )3A1+1.0 hydroxy- 43 30 8.0 23

acetophenone. 10 (i-O4HQ)QAI+1.O ethyl aceto- 43 30 6.3 50

acetate. 11 (i-C4H9)3Al+1.0acety1ace- 48 30 8.3 56

a one.

12 (l-C4P9)3A1+0.5 diethylmalo- 19 30 5.1 64

na e. 13 (i-O-1H )3A1+U.5 phenyl gly- 19 30 3.6 100 oxaldoxime. 14(i-C4H )3Al+0.5 N-phenyl- 19 30 1.4 95

benzohydroxamic acid. 15 (i' C1%0)3A1+0.-5 acetylacetone 19 30 1.1 98

inn e. 16 (i-C4Hg)aA1+0.5 dimethyl 19 30 2.3 100 glyoxime. 17(i-CiHghAH-OA (8-hydroxy- 19 30 1.8 100 quinoline 18 (i O.iH)3Al+0.5mercapto- 2.8 30 0.5 94

benzothiazole. 19 (l-CAEQMAL'lOI (3dietl1yl- 22 30 0.5 100 ammopropanol-20 (i-O4H9)3Al+0.1tetrahydroxy- 19 30 0.6 100 ethyl ethylene diaminc. 21(l-C4H9)2A1H+0.4= (2-dietl1y1- 19 30 0.6 100 amino ethanol) 0%11-1 (0119 .411 19 30 0.5 88

r0 22 (C2H )3A.l+0.5 (2,3'butane- 19 30 15 100 (Hone-2 oxime) 23 (C2H)aAl+0.25 oxalic acid 19 30 2.6 31

EXAMPLE 24 100% n-heptane and double the amount of diluent V Thecatalyst used in Examples 3-16 and 20 was 0.79 part oftriisobutylaluminum chelated with various chelating agents,

and in Examples 17l9 0.4 part of triisobutylaluminurn was chelated. Thecatalyst used in Example 21 was 0.28

part of diisobutylaluminum hydride chelated with 0.4

mole per mole of aluminum of Z-diethylamino ethanol The catalyst used inExamples 22 and 23 was 0.46 part of triethylaluminum chelated withvarious chelating Ten parts of propylene oxide was polymerized by thepolymerization procedure described in Examples 1 and 2 using as diluenta mixture of ether and n-heptane as there and as catalyst 0.46 part oftriethylaluminum chelated With 1 mole of acetylacetone per mole ofaluminum in comparison with a control Where 0.46 part oftriethylaluminum and no chelating agent was used. After 19 hours at 30C., the polymerization was stopped. The poly (propylene oxide) producedwas ether-soluble and was isolated by adding sufiicient ether to makethe solution of low viscosity for ease in handling, then washing thereaction mixture first with a 3% aqueous solution of hydrogen chloride,then with water until neutral, then with a 2% aqueous solution of sodiumbicarbonate and again with water. After adding Santonox, i.e.,4,4'-thiobis(6-tertbutyl-m-cresol), equal to 0.5% based on the polymerto the reaction mixture, the ether was evaporated and the polymer wasdried. The RSVs were determined on a 0.1% solution in benzene at 25 C.The polymer proing agent, had an RSV of 0.19 and amounted to 87% of thetotal polymer whereas that produced with the triethyl- 30 Example 29 wasrepeated for the polymerization of propylene oxide except that thecatalyst used was the chelate formed by reacting 0.57 part ofdiisobutylalumig g 'i gy 3 i i ig t: 5 num hydride with acetylaeetone inan amount of equal to an armoume 0 0 6 3 Poy er P 1.0 mole per mole ofaluminum. The poly(propylene EXAMPLES 25-29 oxide) so produced had anRSV of and amounted to .f Polymerization of Propylene Oxide of the totalpolymer Producedf Ten parts of propylene oxide was polymerized in these10 EXAMPLES 31-36 examples with various chelates of riisobutylaluminumby Epichlorohydrin (10 parts) was polymerized .as dethe same proceduredescribed in Examples 3-11 using scribed in Examples 1 and 2 except thatn-heptane (20.5 n-heptane as the sole diluent. In Examples 28, thetriparts) was used as the diluent and the catalyst Wastriisoisobutylaluminum was reacted with 0.5 mole of thechelatbutylaluminum (0.79 part) chelated with 0.5 mole per ing agen'tper mole of aluminum and in Example 29 with mole of aluminum of variouschelating agents. The 1.0, mole per mole of aluminum. The polymersproduced polymerization was carried out at 30 C. in Example 31 in eachcase were isolated as described in Example 24. and at C. in Examples32-36. The polymer was iso- The reaction time and temperature used ineach case are lated and purified as described in Examples 1 and 2. Inset forth in Table II along with the chelated catalyst ex- Table III areset forth the reaction time and temperature, pressed astriisobutylaluminum+mole of chelating agent 29 the chelated catalystexpressed as triisobutylalumiper mole of aluminum, the RSV of thepolymer (0.1% num+1nole of chelating agent per mole of aluminum, thesolution in benzene at 25 C.) and the amount of the RSV, and amount ofthe ether-insoluble polymer polymer expressed as percent of the totalpolymer. produced.

' TABLE III Ether-insoluble Reaction Total polymer isolated percentExample Catalyst converj Time, Temp, sion' Percent hrs. 0. RSV of totalpolymer Control.-- Lonny/11 19 so so -0.12 31 (i-C4Ha)aAll-0.5(2,3-butane-dione-2-oxime) 19 30 25 6.7 72 Control.-- (i-C Hg)sAl a 1965 62 0.5 6 32 (i-04Hp)aAl+0.5diethyl malonate 19 65 18 0.6 21 33....(i-C4H9)sAl+0.5 dimethy glyoxime 19 65 30 4.9 70 34.. (iC4Ha)sAl+0. 5phenyl glyoxaldoxime 19 65 87 3. 4 86 35.. ('-C4HQ):A1+O. 5N-phenylbenzo-hydroxamic acid. 19 65 25 2. 8 28 36.--- (i-C4H9)3Al+0.5(5-methyl-1,2,3,-cyclohexane-thione-1,3-dioxime) 19 65 84 3. 8 91 TABLEH EXAMPLES 37-46 R r l ggher-ilnsol- Epichlorohydrin was polymerized asdescribed in Exeac u 353.53 amples 1-2 and 31-36 except that 23'parts ofn-heptane 0 W 0 45 was used as the diluent and the catalyst levelwashalf of i g y Percent that used in those examples, i.e. 0.4 part oftriisobu'tyl- 52? 3 6?" RSV 2E32 aluminum chelated with variouschelating agents in varymer ing amount per mole of aluminum. In Examples37-39; 41-44 and 46 the chelated catalyst was aged 'for 1 hour 4 0 19 i65 p at 30 C. before using and in Example 45 for 20 hours 2532 .1-(i-G4H9)sAl+0.5 (2etl10xy- 19 65 2.0 so and in Example 40 the chelatewas aged for 2 days. In 26 igg giffiz hydroxy 19 65 2.1 77 Table IV areset forth the reaction time temperature,

- acetone. h 1 19 65 2 7 I the chelated catalyst expressed astrnsobutylalunngifigl at y 7 V55 num-l-mole of chelating agent per moleof aluminum, the '-O H A1 0.5 acct lacetone. 48 30 5.0 I 23 iacetlacetone 48 65 1m 86 RSV and amount of theetherinsoluble polymer produced.

' TABLE IV v Ether-insoluble Reaction Total polymer isolated 0 t1 t 85 1s w 0 ve Examp e a a y Time, Temp, sion Percent hrs. C. RSV' of totalpolymer Control--- i-0.3 pm 19 30 47 0.15 83 37 (i O4Hs)aAl+0.1(3-diethylamino-1-propan0l) 19 30 78 0.66 s 99 (i-C4H9)3A1+O. 2(3-diethylamino-1-propanol) 19 30 83 0.79 99 (i-O4H9)3Al+0.4(3-diethylaminod-propanol) 19 30 86 0.9 (i-C4H Al+0.4 (aged2 days) 19 3073 3.6 100 (i-C4Hs)sAl+0. 4 (3-di n-butylamine-l-propanol) 19 30 88 1.01100 (l-C4H9)3Al+0.4 (Z-dimethylamino-ethanol) 19 30 88 0.95 100 (i-CH9)aAl+0.4 (2-diethylamino-ethanol)-- 19 30 84 1.35 100(i-CiH9)sA1+0.4m-dietl1ylaminophenol 19 30 81 0.49 100 (i-C4H9);Al+0.1tetrahydroxyethyl ethylene dlamine (aged 20 hours) 19 30 22 V 1.2 30(i-C H Al+0.4ethanolamine 19 30 10 0.31 60 9 EXAMPLE 47 In this exampleethylene oxide and epichlorohydrin were copolymerized. Each of twopolymerization vessels free of air were charged under nitrogen with 40parts of toluene, parts of ethylene oxide and 5 parts ofepichlorohydrin. After equilibrating at 30 C., a solution of thecatalyst was injected. The catalyst used in the control was 0.4 part oftriisobutylaluminum and in Example 47 the catalyst was 0.4 part oftriisobutylaluminum chelated with 0.5 mole of dimethyl glyoxime per moleof aluminum. After agitating the polymerization reaction mixtures at 30C. for 5 hours, the polymerization was stopped by adding 4 parts ofanhydrous ethanol. The copolymer was isolated in each case by adding thereaction mixture to 4 volumes of n-heptane, separating the copolymer byfiltration, washing twice with n-heptane, then with an 0.1% solution of4,4'-thiobis(6-tert-butyl-m-cresol) in n-heptane and drying.

In the example using the chelated triisobutylaluminum catalyst theisolated copolymer was 100% of the total polymer and it was a tough,snappy rubber. In the control, the isolated copolymer amounted to only35% of the total polymer and it was a rubbery solid of obviously muchlower molecular weight.

The foregoing examples clearly demonstrate the many advantages that maybe achieved when a chelated alkylaluminum compound is used as thecatalyst for the polymerization of epoxides. In the majority of casesthere is a large increase in molecular weight, as shown by the increasedRSV of the polymer which may also be accompanied with an increase in theyield of the desired polymer. In other cases, the molecular weight ofthe polymer may not be much different, but there is a great increase inyield of polymer and/ or rate of the polymerization reaction. Obviously,many variations may be made in the process of this invention.

This application is a continuation-in-part of my US. patent applicationSerial No. 738,632, filed May 29, 1958, now abandoned.

What I claim and desire to protect by Letters Patent 1. The process ofpreparing poly(epoxide)s which comprises polymerizing epoxides, whereinthe epoxy group is an oxirane group, by contacting at least one of saidepoxides with, as a catalyst, a chelated organoaluminum compoundcontaining at least one aluminum-to-carbon bond, formed by chelating,under essentially anhydrous conditions, an organoaluminum compound witha chelating agent in an amount such that the molar ratio of chelatingagent to organoaluminum compound is within the range of from about 0.1to about 2, said organoaluminum compound being selected from the groupconsisting of trialkylaluminum compounds and dialkylaluminum hy drides,wherein the alkyl group contains from 1 to 8 carbon atoms, said epoxidebeing free of groups other than oxirane groups which are reactive withsaid organoaluminum catalyst, and said chelating agent is selected fromthe group consisting of polyketones, ketomonocarboxylic acids and estersthereof, ketoaldehydes, hydroxyketones, hydroxyaldehydes,hydroxymonocarboxylic acid esters, hydroxyalkyl monocarboxylates,dicarboxylic acids and esters thereof, dialdehydes, alkoxymonocarboxylicacids, ketooximes, aldooximes, hydroxamic acids, dioximes, aminoalcohols, amino alcohols, ketoimides, aldoimides, and mercaptothiazoles.

2. The process of claim 1 wherein the organoaluminum compound is atrialkylaluminum.

3. The process of claim 1 wherein the organoalurm'num compound is adialkylaluminum hydride.

4. The process of claim 2 wherein the chelating agent is acetylacetone.

5. The process of claim 4 wherein from about 0.3 to about 1 mole ofacetylacetone is reacted with the trialkylaluminum.

6. The process of claim 2 wherein the chelating agent is dimethylglyoxime.

7. The process of claim 6 wherein from about 0.3 to about 1 mole ofdimethyl glyoxime is reacted with the trialkylaluminum.

8. The process of claim 2 wherein the chelating agent is phenylglyoxaldoxime.

9. The process of claim 8 wherein from about 0.3 to about 1 mole ofphenyl glyoxaldoxime is reacted with the trialkylaluminum.

10. The process of claim 5 wherein the epoxide that is polymerized isepichlorohydrin.

11. The process of claim 6 wherein the epoxide is ethylene oxide.

12. The process of claim 6 wherein the epoxide is epichlorohydrin.

13. The process of claim 8 wherein the epoxide is ethylene oxide.

14. The process of claim 8 wherein the epoxide is epichlorohydrin.

References Cited in the file of this patent UNITED STATES PATENTS2,699,457 Ziegler et al Jan. 11, 1955 2,801,228 Starck et al July 30,1957 2,866,761 Hill et al. Dec. 30, 1958 2,870,100 Stewart et al Ian.20, 1959 UNITED STATES PATENT OFFICE OERTIFICATE OF CORRECTION 'atentN00 3 l35 706 June 2 1964 Edwin J, Vandenberg It is hereby certifiedthat error appears in the above numbered patent requiring correction andthat the said Letters Patent should read as corrected below.

Column 4 line 69 for "'of read if g column 7 line ll forriisobutylaluminum" read triisohutylialuminum same column 7' TABLE llunder the heading "Tempo v o CQ'K last line thereof for "65" read 30column 8 TABLE Ill Example 33 under the heading "Catalyst", for'dimethy" read dimethyl column 10, line l3 for "amino'fl, secondoccurrence read imino -u Signed and sealed this 29th day of September1964,,

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner ofPatents

1. THE PROCESS OF PREPARING POLY(EPOXIDE)S WHICH COMPRISES POLYMERIZINGEPOXIDES, WHEREIN THE EPOXY GROUP IS AN OXIRANE GROUP, BY CONTACTING ATLEAST ONE OF SAID EPOXIDES WITH, AS A CATALYST, A CHELATEDORGANOALUMINUM COMPOUND CONTAINING AT LEAST ONE ALUMINUM-TO-CARBON BOND,FORMED BY CHELATING, UNDER ESSENTIALLY ANHYDROUS CONDITIONS, ANORGANOALUMINUM COMPOUND WITH A CHELATING AGENT IN AN AMOUNT SUCH THATTHE MOLAR RATIO OF CHELATING AGENT TO ORGANOALUMINUM COMPOUND IS WITHINTHE RANGE OF FROM ABOUT 0.1 TO ABOUT 2, SAID ORGANOALUMINUM COMPOUNDBEING SELECTED FROM THE GROUP CONSISTING OF TRIALKYLALUMINUM COMPOUNDSAND DIAKYLALUMINUM HYDRIDES, WHEREIN THE ALKYL GROUP CONTAINS FROM 1 TO8 CARBON ATOMS, SAID EPOXIDE BEING FREE OF GROUPS OTHER THAN OXIRANEGROUPS WHICH ARE REACTIVE WITH SAID ORGANOALUMINUM CATALYST, AND SAIDCHELATING AGENT IS SELECTED FROM THE GROUP CONSISTING OF POLYKETONES,KETOMONOCARBOXYLIC ACIDS AND ESTERS THEREOF, KETOALDEHYDES,HYDROXYKETONES, HYDROXYALDEHYDES, HYDROXYMONOCARBOXYLIC ACID ESTERS,HYDROXYALKYL MONOCARBOXYLATES, DICARBOXYLIC ACIDS AND ESTERS THEREOF,DIALDEHYDES, ALKOXYMONOCARBOXYLIC ACIDS, KETOOXIMES, ALDOOXIMES,HYDROXAMIC ACIDS, DIOXIMES, AMINO ALCOHOLS, AMINO ALCOHOLS, KETOIMIDES,ALDOIMIDES , AND MERCAPTOTHIAZOLES.